A method for separating a structure from a substrate through electromagnetic irradiations belonging to a spectral range that is known from the prior art, notably from the U.S. Patent Application Publication US 2002/0068201 A1 (subsequently D1), comprises the steps of:                a) providing the substrate, the substrate being transparent in the spectral range,        b) forming at least one separation layer on the substrate, the spectral range of the electromagnetic irradiations being adapted such that the separation layer(s) are absorbent in the spectral range,        c) forming the structure to be separated on the separation layer(s), and        d) exposing the separation layer(s) to the electromagnetic irradiations via the substrate during an exposure period at a given power density such that the separation layer(s) break down under the effect of the heat stemming from the absorption of the electromagnetic irradiations.        
The structure to be separated can be transferred to a final substrate following separation. The structure to be separated can comprise at least one active layer. “Active” is understood to mean a layer on which or in which there will be produced components that are intended for applications particularly in the field of microelectronics.
In D1, the structure to be separated is a layer produced from a material of (A1, Ga, In)N type. The substrate used in D1 is a substrate called a sacrificial template. D1 envisages one or more separation layers.
Such a separation method from the prior art is not entirely satisfactory insofar as the heat stemming from the absorption of the electromagnetic irradiations by the separation layer(s) is likely to greatly degrade the substrate and/or the structure to be separated, this being all the more so if the substrate and the structure to be separated have substantially different thermal expansion coefficients. This is the reason that the substrate used in D1 is a sacrificial substrate that cannot be recycled. Moreover, the degradation of the structure to be separated is likely to cause degradation of the active layer(s).